<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        table {
            /* 对比cssborder和table自带的border不同 */
            border: 1 px red solid;
            /* cssborder是个外边框 table border内外边框 */
            /* 实现表格变成细线 */
            border-collapse: collapse;
            text-align: center;
            /* 快捷键 bd */

        }
    </style>
</head>

<body>
    <table border="1" width="400">
        <tr>
            <td>id</td>
            <td>姓名</td>
            <td>年龄</td>
        </tr>
        <tr>
            <td>001</td>
            <td>李**</td>
            <td>30</td>
        </tr>
    </table>
</body>

</html>